I use it
public class ExampleFrame extends Frame {

    public ExampleFrame() {
        super("Embedded PApplet");

        setLayout(new BorderLayout());
        PApplet embed = new Embedded();
        add(embed, BorderLayout.CENTER);

        // important to call this whenever embedding a PApplet.
        // It ensures that the animation thread is started and
        // that other internal variables are properly set.
        embed.init();
    }
}

public class Embedded extends PApplet {

    public void setup() {
        // original setup code here ...
        size(400, 400);

        // prevent thread from starving everything else
        noLoop();
    }

    public void draw() {
        // drawing code goes here
    }

    public void mousePressed() {
        // do something based on mouse movement

        // update the screen (run draw once)
        redraw();
    }
}
in class Embedded i use PFont
font=loadFont("AmerigoBT-BoldA-48.vlw");
but it say "Could not load font AmerigoBT-BoldA-48.vlw",in data have this font.